import time
import psycopg2

def connect_postgres():
    return psycopg2.connect(
        host="localhost",
        database="postgres",
        user="postgres",
        password="1"
    )

def create_tables_postgres():
    start_time = 0
    end_time = 0

    sql_command_create_table= (
        """CREATE TABLE airlines
        (
            "IATA_CODE" VARCHAR(2),
            "AIRLINE" VARCHAR(30)
        )
        """,
        """CREATE TABLE airports
        (
            "IATA_CODE" VARCHAR(3),
            "AIRPORT" VARCHAR(100),
            "CITY" VARCHAR(40),
            "STATE" VARCHAR(2),
            "COUNTRY" VARCHAR(40),
            "LATITUDE" REAL,
            "LONGITUDE" REAL
        )
        """,
        """CREATE TABLE flights
        (
            "YEAR" INTEGER,
            "MONTH" INTEGER,
            "DAY" INTEGER,
            "DAY_OF_WEEK" INTEGER,
            "AIRLINE" VARCHAR(2),
            "FLIGHT_NUMBER" INTEGER,
            "TAIL_NUMBER" VARCHAR(6),
            "ORIGIN_AIRPORT" VARCHAR(5),
            "DESTINATION_AIRPORT" VARCHAR(5),
            "SCHEDULED_DEPARTURE" INTEGER,
            "DEPARTURE_TIME" INTEGER,
            "DEPARTURE_DELAY" INTEGER,
            "TAXI_OUT" INTEGER,
            "WHEELS_OFF" INTEGER,
            "SCHEDULED_TIME" INTEGER,
            "ELAPSED_TIME" INTEGER,
            "AIR_TIME" INTEGER,
            "DISTANCE" INTEGER,
            "WHEELS_ON" INTEGER,
            "TAXI_IN" INTEGER,
            "SCHEDULED_ARRIVAL" INTEGER,
            "ARRIVAL_TIME" INTEGER,
            "ARRIVAL_DELAY" INTEGER,
            "DIVERTED" INTEGER,
            "CANCELLED" INTEGER,
            "CANCELLATION_REASON" VARCHAR(1),
            "AIR_SYSTEM_DELAY" INTEGER,
            "SECURITY_DELAY" INTEGER,
            "AIRLINE_DELAY" INTEGER,
            "LATE_AIRCRAFT_DELAY" INTEGER,
            "WEATHER_DELAY" INTEGER
        )
        """)
    try:
        with connect_postgres() as conn:
            with conn.cursor() as cursor:
                start_time = time.time()
                for command in sql_command_create_table:
                    cursor.execute(command)
            conn.commit()
            end_time = time.time()
            cursor.close()
        conn.close()
    except (psycopg2.DatabaseError, Exception) as error:
        print(error)
    return end_time-start_time

def create_data_postgres():
    start_time = 0
    end_time = 0
    sql_command_copy =(
        """COPY airlines FROM 'C://Users//Public//2015_Flight_Delay_and_cancellations//airlines.csv' DELIMITER ',' NULL AS ''""",
        """COPY airports FROM 'C://Users//Public//2015_Flight_Delay_and_cancellations//airports.csv' DELIMITER ',' NULL AS ''""",
        """COPY flights FROM 'C://Users//Public//2015_Flight_Delay_and_cancellations//flights.csv' DELIMITER ',' NULL AS ''""")
    try:
        with connect_postgres() as conn:
            with conn.cursor() as cursor:
                start_time = time.time()
                for command in sql_command_copy:
                    cursor.execute(command)
            conn.commit()
            end_time = time.time()
            cursor.close()
        conn.close()
    except (psycopg2.DatabaseError, Exception) as error:
        print(error)
    return end_time-start_time

def requete_postgres(str):
    start_time = 0
    end_time = 0
    try:
        with connect_postgres() as conn:
            with conn.cursor() as cursor:
                start_time = time.time()
                cursor.execute(str)
            conn.commit()
            end_time = time.time()
            size = cursor.rowcount
            cursor.close()
        conn.close()
    except (psycopg2.DatabaseError, Exception) as error:
        print(error)
    return end_time-start_time, size

def reset_database_postgres():
    start_time = 0
    end_time = 0
    try:
        with connect_postgres() as conn:
            start_time = time.time()
            with conn.cursor() as cursor:
                cursor.execute('DROP TABLE IF EXISTS flights,airlines,airports,flights2')
            conn.commit()
            end_time = time.time()
            cursor.close()
        conn.close()
    except (psycopg2.DatabaseError, Exception) as error:
        print(error)
    return end_time-start_time